Automatic test equipment such as, for example, that used for testing avionics systems, requires internally generated stimuli corresponding to particular paratmeters to be tested, and further requires that the generted stimuli be measured to determine their accuracy. Additionally, it is desirable that the test equipment have the capability of measuring externally generated signals corresponding to the particular parameters.
A common parameter to be tested by test equipment of the type described is synchro/resolver shaft angle, i.e. the angular position of a synchro/resolver shaft. Prior to the present invention, apparatus for generating synchro/resolver shaft angle stimuli and for measuring such stimuli has been somewhat cumbersome, requiring complicated circuitry including switching arrangements and the like. This has been particularly true when stimuli corresponding to various shaft angles need to be generated and measured.
Accordingly, it is the main object of this invention to overcome the aforenoted disadvantages of the prior art by providing apparatus including digital and analog components for generating, via computer interface control, analog synchro/resolver shaft angle output stimuli from digital shaft angle inputs, and for measuring said stimuli by providing digital shaft angle outputs therefrom. The invention has the further capability of providing digital shaftr angle outputs from externally generated analog shaft angle inputs, and for measuring said inputs.
It is another object of the invention to achieve a desirable versatility in that a plurality of independently controlled simultaneously operated signal generating and measuring channels are provided, each of which is responsive to different shaft angle information.